Method of making hard-shell pump-rod couplings and the like



Feb. 26, 1929.

J. L. GRAY ET AL METHOD OF MAKING HARD SHELL PUMP ROD COUPLINGS AND THE LIKE Original Flled Aug 18 1926 b 8 7 M .T T

' INvENnSRs Jess! L. G RAY R s RTVV- UN'N ALQVVILESIEE'ILS Tg om men I UNITED STATES PATENT, OFFICE.

Pans Feb. 26,1929; 1,703,232

JESSE L. GRAY, ROIBEBT W. GUNN, AND WILLSIE A. S. THOMPSON, OF LOS ANGELES, CALIFORNIA, ASSIGNOR S, BY MESNE ASSIGNMENTS, TO EMSGO DERRICK & EQUIP- MENT COMPANY OF LOSAIVGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA.

-METHOD OF MAKING HARD SHELL PUIl IlP-ROD COUPLINGS AND LIKE.

"Original application filed August 18, 1926, Serial No. 129,974. Divided and this application filed October 17, 1927. Serial No. 226,770. v

This invention more particularly relates piece before the metal is case-hardened such to a novel method for making couplings for threads become distorted so that in screwing 55 the sections of sucker rods for deep well the couplings home on the, rod sections there 7 pumps, and which is adapted for the 'manuis likelihood of stripping or wrecking the facture of couplings for pipe, cable ends, threads in parts, thus making the rod likelypiston rods, shafts and turnbuckles and the to pull apart under the tremendous weight of 1 like. This application is a division of our the rod and the column of liquid it hasto lift; 60 application entitled Hard shell pump-rod and ithas been found impracticable to use coupling, Serial No. 129,974, filed August a cou ling. of this character in which the 10 18,1926. threa s are cut into the hardened inside "Where oil wells are sunk togreat dept shell. sometimes exceeding five thousand feet, it This invention is broadly new, basic and is customary to pump oil out of such wells pioneer in that it rovides a method for through pump tubes having foot valves; manufacturing tubu ar couplingshaving a suckers being operated in the tuber for that case-hardened shell and a threaded soft purpose, by means of rods which are made tough steel inside wall and also includes a 5 in sections joined by couplings, each rod exblank from which said coupling is made, tending "from near the bottom of its pump said blank comprising a case-hardened shell tube to above the surface of the ground. and soft steel interior wall. v

The rod sections and their couplings are The advantage of the improved couplingrequired to be of great strength and to" be is that the same can be internally threaded connected with great force so that they will without distortion so as to screw onto the 75 not unscrew or part, and they are subject to threaded ends of the sections to which it is great wear through coming into contact with connected.

- the interior of their tubes as they are re- When the blank is tapped and the ends of I .ciprocated up and down in the operation of the blank are externally bevelled, the coupumping. Such rods of coupled sections 'pling is perfected. are necessarily made of strong tough steel. We have discovered that by first carbon- An object of this invention is to provide izing the surface of a tube, then boring out- 30 a method of manufacturing pump-rod secthe carbonized surface inside the tube and tion couplings or. other couplings having trimming the ends of the tube so as to leave superior wearing qualities, and yet being a central tubular. body of non-carbonized strong and tenacious and not likely to break stock exposed at the ends and at the surface nor wear. of the bore, then hardening the carbonized 35 It is desirable particularly in pump-rod surface and then tapping the bore, it IS couplings that the same shall have absolutely possible to make a coupling externally hard true interior threads to exactlyv fit the and internally tough and screw-threaded, threads on the sucker rod sections and it is adapted to be screwed so tightly onto 'the also desirable that the couplings have a hard threaded pins' of the connecting rod sections 40 and polished exterior s0 that they will not as to make the rod practically integral from cause friction, will not'become worn, and will end to end, free from likelihood of unscrewnot wear the tubing-excessively. ing and from wearing at the joints; and An object of this inventionis to make a that by polishing the outside of the coupling pump-rod coupling having these important it is less subject to wear the tubing and to be 45 and valuable features. worn thereby Attempts have heretofore been made to An object is to provide a novel method of provide sucker rod couplings having hard manufacturing a coupling that will carry a wearing surfaces, but in orderto provide'the high exterior polish so as to operate smoothly coupling with a hard surfaceit isnecessary with respect to the well tube. to heat the coupling steel to a requisite heat An advantage from the'use of a coupling and then quench the heat; to give the steel a having a hard carbonized 'peripheralshell hardened surface; but it is found that if the and asoft*and tough tubular threaded core,

thread is cut in the bore of the coupling having ends projecting beyond the shell, is

ing 'the same, Serial No. 129,974. filed Aug.

18, 1926; and the discovery and invention may be understood by reference to the acc'ompanying drawing which is a replica of the drawing filed insaid application.

Figure 1 'is a of cold rolled steel screw stock of which the coupling is to be made.

Fig.2 is a like view of such ready for carbonizing.

Fig. 3 is a perspective view in axial section on line (a Fig. 2, after carbonizing and before hardening.

Fig. 4 is an axial section of the periplierally carbonized blank after the ends have been turned and the carbonized inside lining has been bored'out.

Fig. 5 is an axial section of the trimmed and externally case-hardened coupling length, bored ored blank.

Fig. 6 is an axial section of ened internally tough rod coupling ready for use.

Fig. 7 is a perspective View of the finished coupling. a

Fig. 8 is a fragmental view of the coueter. Such stock is soft steel low in carbon.

To produce pum rod couplings of ,said

standard size embo ying this invention, we

out such stock into four and one eighthinch lengths such-as shown at 1 in Fig.- 1; the

same bein required o one-eighth inch longer than is r the proposed standard rod coupling.

Each cutor length 1, is drilled with a} central boreo: five-eighths inch in diameter, thus leavin a tubular body 2 that is oneh aIf inch th1ck all around outside the bore w;

The tubular screw stock length 2 thus formed, is then carbonized-by enveloping external shell by perspective view of a length.

are externally chamfered.

. the bored, threaded and trimmed externally case-hardpressed or jammed common to t e art.

the same in a case-hardening substance such as bone meal, illuminating gas, cyanide of potassium or any well known material, not

shown, commonly used for case-hardening;

and the same is sufficient heat for a carbonized outside'she'll b, a carbonized inside lining a and carbonized ofsteel extending on all surfaces to the depth of about one-sixteenth of an inch, thus producing a superficially carbonized tube 3 having a tough soft steel in a carbonized case b, c,

The tube is then cooled and the inside carbonized steel lining c is drilled out as indicated at 4 to a diameter of bore suitable to receive the selected thread, as for instance to a diameter of fifty-seven sixty-fourths inch; fifty-eight sixty-fourths inch; fiftynine sixty-fourths inch or sixty one sixtyfourths inch, respectively, for the customary different threading of the coupling rod pins. The end facings (Z are cut off and the ends brought to, and held at, a

ing a coupling blank 5, having a tough soft steel screw stock body 6 with tough soft steel inside walls and projecting chamfered soft steel ends it. Then the coupling blank 5 is heated to a requisite temperature for hardening and is then-"quenched by immersing in water or other suitable liquid thus in soft steel body 6 and soft steel projecting ends 8. 4

body 6 enveloped as at f thus formproducing a hardened-coupling blank 5 hava case-hardenedsteelshell b and atough a sufiicient time to produce end facings d Then the soft steel inside wall of the hardened coupling blank is tapped to form the coupling 6 having internal threads If to fit the threads of the pinsp of the pump rodsections 7 of the common construction 'indi-. 1 05 cated in Fig. 8.

In practical assembly, the threaded sucker rod lengthsand the conplings are forcibly and the collars'of the rod section are com- The polishing may be effected b grinding or by any method It is obvious that our improved process is screwed together with the result that the soft steel ends of the body together with the same couplings were not pro-- readily adaptable for use in making coua plings-for pipe turnbuckles and o It is also understood that althoughthe body of the blank cable, piston rods, shafts,

plump rod, the i and is. adapted to take on having the i e internal tough f the finished couther mechanical couplings.

.5 is shown as, mainly We have determined, by exhaustive tests since filing the parent application above recylindrical, that ferred to, that the polishing of the shell is a plings, becomes very very important feature of this inventiorr for the reason that unless. the polishing is effected as stated, there remains on the shell a thin skin or outside envelope of slight depth, composed of steel decarbonized by the hardening process, and that if such decarbonized steel is not r moved by it acts as a detergent to grind and wear the inside of the pump tubing to a destructive extent and the use of a sucker rod the depths of which are joined by such unpolish'ed coudetrimental, objectionable, and is destructive-of the pump tubing in which the rod is operated; but with the polished coupling as above stated, no such wearing results. Such detergent skin may be only one thousandth or two thousandths of an inch thick and yet be very detrimental in use in pump tubing as before stated.

We claim 1. The method of making a pump rod coupling set forth which consists in boring a length of soft steel stock, carbonizing the surface of the tube'thus formed; removing the carbonized surface inside and at the ends of the tube; hardening the tubular blank thus formed by heating to a requisite temsuitable liquid and then tapping the bore.

2. The method set forth of making a pump rod coupling which consists in boring a length ofsoft steel stock, carbonizing the surface of the tube thus formed; removing the carbonized surface inside and at the ends of the tube; hardening which consists in boring a the polishing process,

-ized surface inside and erature; then quenching in water or other the surface of the tubular blank thus formed by heating the same to afequisite temperature and then quenching in water or other suitable liquid,

then tapping the bore and grinding the out-- side surface to form a polished perimeter.

3. The method of making couplings, length o f'soft steel stock, carbonizing the surface of the body thus formed, removing surface-inside the bore and at the ends of the body; hardening the surface of the tubular blank thus formed by heating the same to a' requisite temperature, then quenching in water or other suitable liquid and then tapping the bore.

, 4:. The method set forth of making a coupling which consists in boring 'a length of soft steel stock, carbonizing the-surface of the body thus formed; removing the carbonat the ends of the hardening the surface of the tubular blank thus formed by heatin the same to a requisite temperature and then quenching in water or other suitable liquid, then taping the borea'nd grinding the outside surface to form a hardened, polished perimeter.

5. The method set forth of making a couling which consists in boring a length of soft steel stock; carbonizing the surface of the body thus formed; hardening the surface of the tubular blank by heating the same to a requisite temperature, quenching in water or other suitable liquid, then tap ing the bore and grinding the outside sur ace to forma hardened, polished perimeter. v

In testimony whereof, we have hereunto body set our hands at Los Angeles, California, this 3 3d day of October, 1927.

JESSE L. GRAY ROBERT W. GUNN. V WILLSIE A. S. THOMPSON.

the carbonizedthen 

